NYET!!!
These people are stupid! Sorry to be cranky.
FAST ON is a trade name. Through BITTER HARD EARNED EXPERIENCE I learned standard SPADE TERMINALS S-U-C-K when conducting high amperage. Yeah. Fires.
Do whatever it takes to find larger wire size PACKARD female terminals. They have a ramp tang inside that increases conductive area contact surface.
I've not seen anything larger than 10-12 gauge Packard terminals and they are never encased. Always bare. With care solder 10 gauge AWG wire to the inside tang then crimp the top tang to the wire insulator. I cover with 3:1 heat shrink tubing.
When I built the BORG I soldered 3 into 1 wires directly to the terminal block screws and all.
Slip-on .250" fast on terminals should always have to be babied on. Tight tight tight. Silicone GREASE helps. My comments are derived from decades of experience not theory. Fast On and me butted heads. I had to fix factory and other technician's screwups.